R. KR. Bensley 109 
the cesophageal groove in the sheep. If the glands are really of im- 
portance as sources of a digestive ferment, it is difficult to understand 
why they have disappeared in a group of animals in which their pres- 
ence would be such an immense advantage. One would rather expect 
that the processes of natural selection would tend to preserve and per- 
fect them. The importance of the occurrence of an amylolytic ferment 
in the cardiac mucosa is materially reduced by many recent researches 
which go to show the widespread occurrence of sugar-splitting ferments 
in the blood and tissues of mammals, and by the observation of Ellen- 
berger and Hofmeister that a diastatic ferment is present in the fundus 
mucosa of the pig where, owing to the acidity of the gastric secretion, it 
could be of very little service in digestion. 
In the present state of our knowledge it does not seem possible to 
assign any definite function to the cardiac glands, nor does investiga- 
tion by physiological methods appear to offer much hope of solving this 
problem. It seems to the writer that the first step in the further eluci- 
dation of these glands must consist in the comparison of them, as tre- 
gards structure, staiing, and microchemical reactions and mode of 
regeneration, with the other glandular elements of the stomach. It is 
true that both Edelmann and Schaffer have instituted comparisons of 
this kind, but at the time of the publication of Edelmann’s paper, no 
adequate description of the structure of the chief cells and pyloric cells 
existed, and Schaffer’s comparison of the cardiac gland cells with the 
chief cells as well as the pyloric gland cells shows clearly that he was 
unaware of the important differences between the two. 
Another problem which must be considered in connection with the 
question of the histology of the glands is that of their phylogeny. The 
fact that only fundus and pyloric glands are represented in reptiles and 
batrachians makes the question of the source of the cardiac glands a 
very interesting one. Are they to be regarded as derived from pre- 
existent structures, for example, as cesophageal glands which have been 
taken over into the stomach, or fundus glands which have been pecu- 
harly modified, or finally as ccenogencetic structures which have arisen in 
Mammalia in response to a new functional demand? Oppel, 96, has 
suggested, but in a tentative rather than an assertive mood, that they 
may represent the simple glands of lower vertebrates, which have not 
all been differentiated into the complex fundus glands of mammals, but 
admits that the great structural differences are scarcely compatible with 
such a view. Edelmann contents himself with stating their possible 
sources of origin without attempting to decide between them. More 
recently Oppel, in a brief discussion of Schaffer’s discovery of parietal 
